I have a heat lamp with two 75 watt infrared bulbs inside going on timers (acting like a thermostat until I get one) and a little space heater running to keep the room at 70-73 degrees. I just added four Dixie cups full of moss and it bumped my humidity up by 5% or so. It sits around 57-65% now. We've got foil covering 90% of the top too. Just enough holes in the foil for airflow. I might be switching to a CHE instead of the two bulbs but I'm not 100% I want to yet. There's no UTH right now because he's healing and I don't want to change too much at one time.

* I did have a 100watt infrared bulb and it was harder to maintain the humidity. Is your light on a thermostat dimmer at all?
* if your room temps are sitting at 60-67 and it's a glass tank I would definitely get some blue insulation board for 3 sides of the tank and use a small space heater to bump up the room temps. I read somewhere that warmer air holds more humidity.

oh and what are you using to read temps/humidity?